// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/big_endian.h"

#include <stdint.h>

#include "base/strings/string_piece.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace base {

TEST(BigEndianReaderTest, ReadsValues)
{
    char data[] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0xA, 0xB, 0xC, 0xD, 0xE, 0xF,
        0x1A, 0x2B, 0x3C, 0x4D, 0x5E };
    char buf[2];
    uint8_t u8;
    uint16_t u16;
    uint32_t u32;
    uint64_t u64;
    base::StringPiece piece;
    BigEndianReader reader(data, sizeof(data));

    EXPECT_TRUE(reader.Skip(2));
    EXPECT_EQ(data + 2, reader.ptr());
    EXPECT_EQ(reader.remaining(), static_cast<int>(sizeof(data)) - 2);
    EXPECT_TRUE(reader.ReadBytes(buf, sizeof(buf)));
    EXPECT_EQ(0x2, buf[0]);
    EXPECT_EQ(0x3, buf[1]);
    EXPECT_TRUE(reader.ReadU8(&u8));
    EXPECT_EQ(0x4, u8);
    EXPECT_TRUE(reader.ReadU16(&u16));
    EXPECT_EQ(0x0506, u16);
    EXPECT_TRUE(reader.ReadU32(&u32));
    EXPECT_EQ(0x0708090Au, u32);
    EXPECT_TRUE(reader.ReadU64(&u64));
    EXPECT_EQ(0x0B0C0D0E0F1A2B3Cllu, u64);
    base::StringPiece expected(reader.ptr(), 2);
    EXPECT_TRUE(reader.ReadPiece(&piece, 2));
    EXPECT_EQ(2u, piece.size());
    EXPECT_EQ(expected.data(), piece.data());
}

TEST(BigEndianReaderTest, RespectsLength)
{
    char data[8];
    char buf[2];
    uint8_t u8;
    uint16_t u16;
    uint32_t u32;
    uint64_t u64;
    base::StringPiece piece;
    BigEndianReader reader(data, sizeof(data));
    // 8 left
    EXPECT_FALSE(reader.Skip(9));
    EXPECT_TRUE(reader.Skip(1));
    // 7 left
    EXPECT_FALSE(reader.ReadU64(&u64));
    EXPECT_TRUE(reader.Skip(4));
    // 3 left
    EXPECT_FALSE(reader.ReadU32(&u32));
    EXPECT_FALSE(reader.ReadPiece(&piece, 4));
    EXPECT_TRUE(reader.Skip(2));
    // 1 left
    EXPECT_FALSE(reader.ReadU16(&u16));
    EXPECT_FALSE(reader.ReadBytes(buf, 2));
    EXPECT_TRUE(reader.Skip(1));
    // 0 left
    EXPECT_FALSE(reader.ReadU8(&u8));
    EXPECT_EQ(0, reader.remaining());
}

TEST(BigEndianWriterTest, WritesValues)
{
    char expected[] = { 0, 0, 2, 3, 4, 5, 6, 7, 8, 9, 0xA, 0xB, 0xC, 0xD, 0xE,
        0xF, 0x1A, 0x2B, 0x3C };
    char data[sizeof(expected)];
    char buf[] = { 0x2, 0x3 };
    memset(data, 0, sizeof(data));
    BigEndianWriter writer(data, sizeof(data));

    EXPECT_TRUE(writer.Skip(2));
    EXPECT_TRUE(writer.WriteBytes(buf, sizeof(buf)));
    EXPECT_TRUE(writer.WriteU8(0x4));
    EXPECT_TRUE(writer.WriteU16(0x0506));
    EXPECT_TRUE(writer.WriteU32(0x0708090A));
    EXPECT_TRUE(writer.WriteU64(0x0B0C0D0E0F1A2B3Cllu));
    EXPECT_EQ(0, memcmp(expected, data, sizeof(expected)));
}

TEST(BigEndianWriterTest, RespectsLength)
{
    char data[8];
    char buf[2];
    uint8_t u8 = 0;
    uint16_t u16 = 0;
    uint32_t u32 = 0;
    uint64_t u64 = 0;
    BigEndianWriter writer(data, sizeof(data));
    // 8 left
    EXPECT_FALSE(writer.Skip(9));
    EXPECT_TRUE(writer.Skip(1));
    // 7 left
    EXPECT_FALSE(writer.WriteU64(u64));
    EXPECT_TRUE(writer.Skip(4));
    // 3 left
    EXPECT_FALSE(writer.WriteU32(u32));
    EXPECT_TRUE(writer.Skip(2));
    // 1 left
    EXPECT_FALSE(writer.WriteU16(u16));
    EXPECT_FALSE(writer.WriteBytes(buf, 2));
    EXPECT_TRUE(writer.Skip(1));
    // 0 left
    EXPECT_FALSE(writer.WriteU8(u8));
    EXPECT_EQ(0, writer.remaining());
}

} // namespace base
